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GIP: Glucose-dependent Insulinotropic Peptide

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00239707
Recruitment Status : Completed
First Posted : October 17, 2005
Last Update Posted : November 28, 2013
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) )

Brief Summary:
The purpose of this study is to test the safety of glucose-dependent insulinotropic peptide (GIP)/GIP Analog on people with Type 2 Diabetes.

Condition or disease Intervention/treatment Phase
Type 2 Diabetes Drug: GIP Drug: Modified GIP Drug: Normal Saline Phase 1

Detailed Description:

The small bowel makes a hormone called glucose-dependent insulinotropic peptide (GIP). It is released into the blood stream and goes to the pancreas. It works there with nutrients, especially glucose, in the digested food so that insulin is released in sufficient amounts from the pancreas. The insulin causes the nutrients from the food to be stored in the liver, fat and muscle until they are needed to provide energy. GIP also slows emptying of food from the stomach, which decreases the rate with which fats in food are broken down and stored. Once it is released into the blood, GIP is quickly broken down and becomes inactive. Individuals with type 2 diabetes do not make enough GIP and pharmacological doses of naturally occurring GIP do not increase insulin secretion in patients with type 2 diabetes. This study is testing a modified GIP (it had one amino acid difference from naturally occurring human GIP) that is not broken down as quickly in individuals with type 2 diabetes, to determine if it will improve insulin secretion, after eating, in patients with type 2 diabetes. The study will also compare its effects to that of naturally occurring, human GIP. Both human GIP and the modified GIP (GIP analog) are manufactured by peptide synthesis techniques (not extracted from human gut and not recombinant technology).

A screening visit will be performed including blood work, EKG and physical exam. If eligible, patients would be scheduled for three infusion visits 2 months apart, where they will receive a normal saline infusion on the first visit and GIP or GIP analog on the remaining visits. The infusion visits will begin approximately 6:45 a.m. and patients will have frequent blood sampling through an intravenous line over a period of 7 hours. An additional intravenous line will be placed for the infusion of either the normal saline, GIP or GIP analog over a period of 3 hours. Patients will be given a breakfast meal consisting of 550 calories (one egg, piece of toast with margarine, corn flakes 2% milk and a banana). They will be given 2 Extra-Strength Tylenol to determine time frame that food is emptied from stomach by measuring Tylenol levels in the blood. At the end of each study visit, patients will be given lunch, intravenous lines will be discontinued and they will be discharged to home.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 41 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Effect of GIP / GIP Analog in Type 2 Diabetes After a Meal
Study Start Date : February 2003
Actual Primary Completion Date : December 2006
Actual Study Completion Date : December 2006

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Infusion 1
Normal Saline
Drug: GIP
One-time 20 ng/kg/min infusion over 3 hours
Other Name: Glucose dependent insulinotropic peptide

Placebo Comparator: Infusion 2
GIP or modified GIP
Drug: Modified GIP
One-time infusion over 3 hours; dose to maintain desired biological effect of below 140 mg/dl
Other Name: GIP analog

Placebo Comparator: Infusion 3
GIP or modified GIP, opposite of Infusion 2
Drug: Normal Saline
one-time infusion over 3 hours
Other Name: Saline

Primary Outcome Measures :
  1. GIP, glucose, insulin measured frequently during infusions [ Time Frame: baseline, 2 months, and 4 months ]

Secondary Outcome Measures :
  1. GLP-1, ghrelin measured frequently during infusions [ Time Frame: baseline, 2 months, and 4 months ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • 18 years of age and older
  • Healthy Type 2 Diabetics
  • Agree to stay off glucosidases for 3 days prior to infusion visits (Examples: Precose, Glyset)
  • Agree to stay off Sulfonylureas 5 days prior to infusion visits (Examples: Glucotrol, Amaryl, glyburide, metformin
  • Able to ingest 1000 mg Tylenol on study visits
  • Able to consume study breakfast consisting of scrambled egg, white toast with margarine, corn flakes, 2% milk, banana at each infusion visit
  • Female participants must have Hct > 36
  • Male participant must have Hct > 38
  • No kidney or liver disease per history and evidenced by blood and urine tests
  • Physical Exam and EKG that do not contraindicate patient to be in the study

Exclusion Criteria:

  • Taking the following medications: Insulin, or Thiazolidinediones, i.e. Avandia, Actos
  • Pregnancy
  • Steroid use within the past 3 months
  • Recent infection, fever or chills

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00239707

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United States, Maryland
National Institute on Aging, Clinical Research Branch
Baltimore, Maryland, United States, 21225
Sponsors and Collaborators
National Institute on Aging (NIA)
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Principal Investigator: Josephine Egan, MD Chief, Diabetes Section, National Institute on Aging
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: National Institute on Aging (NIA) Identifier: NCT00239707    
Other Study ID Numbers: AG0056
First Posted: October 17, 2005    Key Record Dates
Last Update Posted: November 28, 2013
Last Verified: November 2013
Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) ):
insulin sensitivity
blood sugar
Additional relevant MeSH terms:
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Diabetes Mellitus, Type 2
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Gastric Inhibitory Polypeptide
Gastrointestinal Agents
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs